1. Field of the Invention
The present invention generally relates to tools for use in installing, removing, raising and/or lowering various kinds of workpieces and, more particularly, is concerned with an erecting tool for lifting and extending an articulated flat plate, such as used at a truck loading and unloading dock, from a partially folded storage condition to a flat deployed condition.
2. Description of the Prior Art
A typical truck dock at a commercial or industrial facility is a platform located above the ground at a standard elevation or height matching that of a truck bed above the ground. For loading and unloading purposes, a truck is backed up to the dock until the rear end of the bed of the truck makes contact with bumpers protruding from the dock. The rear end of the truck bed is then spaced a short distance from the front edge of the dock, creating a gap therebetween which has to be bridged in order to safely and efficiently load or unload goods to or from the truck bed.
A widespread practice is to provide an articulated flat plate which is extendable between the dock and truck bed over the gap. The articulated plate is pivotally connected by a first hinge to a flat mounting plate attached vertically to the front edge of the dock. The articulated plate also has a second hinge pivotally connecting a pair of flat front and rear portions of the plate along a line extending generally parallel to and spaced approximately midway between front and rear edges of the plate. The first hinge is disposed along the front edge of the dock and constructed to limit the rear portion of the articulated plate to pivotal movement upwardly away from and downwardly toward a generally horizontal orientation relative to the vertically-oriented flat mounting plate in which the rear portion of the articulated plate projects outwardly from the front edge of the dock. The second hinge is spaced forwardly from the first hinge and thereby from the front edge of the dock and is constructed to allow the front portion of the articulated plate to normally hang vertically downward from the second hinge and the rear portion of the articulated plate.
The second hinge is also constructed to allow the flat front and rear portions of the articulated plate to only pivot through approximately 180.degree. relative to one another between a fully extended relationship and a one-way folded relationship. In the fully extended relationship, the front portion of the articulated plate is angularly displaced generally 180.degree. from the rear portion of the plate. Thus, the flat front and rear portions of the plate are oriented in a substantially coplanar relationship with one another which converts the articulated plate to a generally flat deployed position in which it is capable of spanning the gap between the dock and truck bed. In a partially folded relationship, in which the front and rear portions of the articulated plate are disposed approximately halfway between the fully extended and one-way folded relationships, the front portion of the articulated plate is disposed at an angle about midway between 0.degree. to 180.degree., or about 90.degree., relative to the rear portion of the plate which places the articulated plate in a partially folded storage condition in which the front portion of the plate hangs downwardly from the front edge of the rear portion of the plate.
To convert the articulated plate from the partially folded storage condition to the fully extended or flat deployed condition, the conventional practice is for a dock worker to use a meat-type hook. The dock worker has to bend over the front edge of the dock and reach down and engage the lower front edge of the front portion of the articulated plate with the hook. While still in the bent-over position, the dock worker then has to pull upwardly to lift both portions of the articulated plate and to pivot the front portion of the plate relative to the rear portion thereof in order to convert the articulated plate to the fully extended deployed condition.
It can be easily realized that such practice can frequently cause back strain and injury to the dock worker and result in a workman's compensation claim. Consequently, a need exists for a tool to assist a dock worker in converting the articulated plate from the partially folded storage condition to the fully extended or flat deployed condition so as to avoid the problems of the above-described prior art practice.